memory management with mmap

[Chetan Nanda]

On Oct 28, 2012 11:49 AM, "Sengottuvelan S" <sengottuvelan.s at gmail.com>
wrote:
>
>
> Hi Mulyadi
>
> I am able to do mmap and access virual-memory address and pages for a
single process from user-space and working fine. I am not sure how to do it
for multiple processes for shared resources using mmap.  I better explain
in detail here what I am experimenting it.
>
> for example:
>
> Kernel allocates kmalloc or vmalloc of 100 pages and set those pages
as reserved. Kernel uses these pages to send/receive data to Process A or B
depends on a condition.
>
> Process A and B do mmap those region to get/set data on those
virtual-addresses/pages because I want faster access from userpace to
kernel.
>
> Anyone knows if this will work with mmap?. Please let me know  if
anyother way to do it.
>
Not sure about your actual requiremnent, but there are other better way of
sharing data between processes already exist. E.g. Shared memory.
Advisable to use them instead of writing a new one

> On Sat, Oct 27, 2012 at 10:57 PM, Mulyadi Santosa <
mulyadi.santosa at gmail.com> wrote:
>>
>> Hi...
>>
>> On Thu, Oct 18, 2012 at 3:02 AM, Sengottuvelan S
>> <sengottuvelan.s at gmail.com> wrote:
>> > For example,
>> >
>> > I have 2 different user space process A,B etc. I have to allocate
memory in
>> > Kernel for each of those processes (for example 2 pages) .  Each
process is
>> > allowed to use only 1 page using mmap from user space.
>> >
>> > Is it possible to do with mmap?.
>>
>> Not sure, but I guess better to do it directly with page_alloc...or at
>> least kmalloc() to better utilize slab.
>>
>> The thing that I think is hard to do, is to implement protection
>> scheme to make sure say process A won't access page allocated by
>> process B.
>>
>> Hopefully I understand your goal correctly.
>>
>>
>> --
>> regards,
>>
>> Mulyadi Santosa
>> Freelance Linux trainer and consultant
>>
>> blog: the-hydra.blogspot.com
>> training: mulyaditraining.blogspot.com
>
>
>
>
> --
> Regards,
> S. Sengottuvelan.
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20121101/1bcb9152/attachment.html